Figs 5 A, 6 C, 18 C
Material studied. Holotype male. CANADA, Yukon, Ogilvie Mountains, North Fork Pass, 4100 ft, 20.VI.1962, R.E. Leech (in CNC).
Description. Male. Head. Colours faded in the specimen studied. Eye bridge 3 facets wide. Setae of face not detectable in the specimen studied. Clypeus with 3 setae. Maxillary palpus with 3 segments, 3 rd segment longer than 1 st segment, 2 nd segment shortest; 1 st segment with 9 setae, with a dorsal patch of sensilla; antennae missing in the specimen studied. Thorax. Colours faded in the specimen studied. Anterior pronotum with 9 setae. Proepisternum with 18 setae. Scutellum with 5 longer and some short and fine setae. Wing. Fumose. Length 2.8 mm. Width/length 0.40. Anal lobe weak. Veins distinct. c/w 0.55. R 1 /R 0.60. stM shorter than fork of M. r-m 2x as long as bM, bM and r-m non-setose. Legs. Colours faded in the specimen studied. Fore tibial organ forming a large patch in depression. Fore tibial spur slightly longer than the tibial width. Abdomen. Colours faded in the specimen studied. Hypopygium (Fig. 5 A). Colours faded in the specimen studied. Intergonocoxal area long, with two setose lobes (Fig. 18 C). Gonocoxa broad, slightly longer than gonostylus, medial margin basally rather strongly curved, with short sparse setosity. Gonostylus (Fig. 6 C) broad, apically tumid, strongly impressed; with short dense setosity, with a rather long apical tooth, with about 15 slender and rather short perpendicular megasetae; with 1 well-differentiated whiplash seta on ventromedial margin. Tegmen apically narrowed and truncated, laterally roundish, weakly sclerotized, aedeagal teeth not detectable in the specimen studied. Aedeagal apodeme long.
BIN. Unknown.
Discussion. By its broad and apically tumid gonostylus which is subbasally strongly broadened and which has numerous short megasetae, Trichocoelina hians sp. n. resembles T. hiemalis (Mohrig & Mamaev), T. incrassata sp. n. and T. magnifica sp. n. Trichocoelina hians differs from T. hiemalis in having the gonostylar apex broader and the apical tooth and megasetae shorter but intergonocoxal lobes of hypopygium longer, see Fig. 5 A and fig. 4 in Mohrig et al. (1985b). Trichocoelina hians differs from T. incrassata and T. magnifica in having its gonostylus slightly narrower and lacking a subbasal lobe with a group of megasetae. From T. incrassata it differs also in having its tegmen less modified, laterally smoothly curved. Furthermore, Trichocoelina hians differs from T. magnifica in having all gonostylar megasetae of the same size, perpendicular and not arranged in groups, and in having shorter intergonocoxal lobes. See also under T. absidata sp. n.
Etymology. The name is Latin, hians, opened, referring to its medially strongly excavated gonostylus.